Trimming head for metal cans

ABSTRACT

A trimming head for metal cans having a cutter rotating against a stationary cutter ring. The can end to be trimmed is fitted inside the stationary exterior cutting ring. As the interior cutter rotates, it cuts the can end off to leave the can at a uniform length. A knockout ring ejects the scrap, and the trimming head is ready for the insertion of another untrimmed can end.

United States Patent Bozek 51 Mar. 7, 1972 [54] TRIMMING HEAD FOR METALCANS [21 Appl. No.: 869,694

[52] 0.5. CL ..82/82, 82/47, 82/101 [51] Int. Cl. 231) 3/04, 1823b 5/14,B231) 1/00 [58] Field of Search ..82/46, 82, 101

[56] References Cited UNITED STATES PATENTS 1,622,253 3/1927 Putt et a1...82/32 1,807,671 6/1931 Phelps 2,342,246 2/ 1944 Bruekner ..32/82 I9 9gh] fill i 2,443,963 6/ l 948 Ricciardi ..82/82 FOREIGN PATENTS ORAPPLICATIONS 818,366 8/ 1959 Great Britain ..82/82 PrimaryExaminer-Harrison L. Hinson AttorneyAmericus Mitchell, Joseph E. Kerwinand William A. Dittrnann ABSTRACT A trimming head for metal cans havinga cutter rotating against a stationary cutter ring. The can end to betrimmed is fitted inside the stationary exterior cutting ring. As theinterior cutter rotates, it cuts the can end off to leave the can at auniform length. A knockout ring ejects the scrap, and the trimming headis ready for the insertion of another untrimmed can end.

8Claims,4Drawing Figures PATENTEDMAR 7 I972 3, 646,840

SHEET 1 [IF 2 INVENTOR i JOHN S. BOZEK ATT'Y PAIENTEBMAR 7 I972 sum 2 UF2 INVENTOH JOHN S. BOZEK ATT'Y TRIMMllNG HEAD FOR METAL CANS Myinvention relates to a trimming device for cylindrical objects, andespecially to a high-speed trimming device for cans.

In the prior art, there are several types of trimming devices, such as amilling-type device, and a shear-type cutter. These devices have variousproblems in operation, such as that of preventing the can from turningin the can holder and dispensing long, springlike chips. The problems ofdisposing of the scrap ring cutoff from the can and the elimination ofthe slivers which may be created during trimming are also found indevices of the prior art.

It is an object of my invention to trim cylindrical elements to auniform length.

It is another object of my invention to trim cylindrical elements with asingle rotary motion of the cutter without developing cracks, burrs, orslivers.

It is a final object of my invention to trim cylindrical elements bytrimming with a high-speed operation and, at the same time, turning theburr outward.

In brief, my apparatus is operated by sliding a movable inside cutteracross a stationary outside cutter ring. The cylindrical object or canis disposed with its open end inside the stationary cutting ring. Thecan is placed squarely down and inside the cutting ring. The activecutting element is an inside cutter. This cutter rotates rapidly and isgradually moved offcenter by a built-in cam mechanism. The inside cuttershears off the surplus portion of the can against the exterior cuttingring. A knockout ring moves the scrap ring out of the die into a scrapcatcher. The machine is now ready for another cycle.

Other objects of the invention will become apparent from the followingspecification and the drawings relating thereto and from the claims setforth.

FIG. 1 shows a view of my device with sections cut away.

FIG. 2 shows an end view of my device, taken from the right-hand side.

FIG. 3 shows a section taken along the line 33 of FIG. 1.

FIG. 4 shows a top view of the stud shaft and main shaft.

My invention is illustrated to best advantage in FIG. 1. In this FIGUREas shown, a can holding fixture 1 is used to move a can or can body 2from the extreme right-hand position up to the trimming head 3. The canis then guided by a stationary ring 4 into the exterior cutting ring 5and over the cylindrical body of the knockout slide 6. The height of thecan is predetermined by the distance between the cutting edge 7 and theinside bottom of the collet 8. During the actual trimming, the can issupported at three points, one in the collet, second in the guiding ringnear the trim line, and third at the trim line.

In essentials, my apparatus has a stud shaft 9 mounted slideably into arotatable main shaft 10. The peculiar mounting of the stud shaft ontothe shaft is one of the reasons for the success of my operation. Thesliding section of the stud shaft 9 has a T-shape and fits into a slot11 in the end of the shaft 10. (FIGS. 1 and 4). The T is secured in theslot, with the capability to slide along the length of the slot. Itsvertical protrusion 12 projects from it and serves as a shaft for theinside cutter 13. The stud shaft 9 is drilled along the length of the Tas shown in FIGS. 1 and 4, and two pins 15, 16 are inserted in thisopening. One pin 15 is fastened immovably to the T stud while the otherpin 16 has a slip fit. A compression spring 17 is inserted in theopening between the two pins to keep the movable pin 16 always engagedin the groove 18 of the cam sleeve, while the position of the fixed pinin relation to the cam sleeve determines the eccentricity of the cutter13 in relation to the main shaft 10. The main shaft is rotated by apulley 19 attached to its other end. Mounted about the length of theshaft 10 is a sleeve 20 which is in its principal function a cam sleeve.At the cutter end of the sleeve is a cam 21 which coacts with the fixedpin to cause the T-stud to move offcenter when the sleeve is movedforward to move the stud shaft in an upward direction as shown inFIG. 1. Actually, the cam causes the pin 15 to move toward the axis ofrotation of the shaft and the cutter 13 to move away from the axis. Abearing ring 22 is mounted about the sleeve and attached to the bearingring are trunnions 23 which project outwardly through the housing 24 andare actuated by a bifurcated element 25. One end 26 of the bifurcatedelement is attached to an air cylinder 17 or the like for shifting theelement 25 and the trunnions 23 back and forth. The main shaft 10 andsleeve 20 are keyed together by key 28 and rotate together.

Mounted adjacent the outer cutting ring 4 is a knockout ring 29. On theleft side of the knockout ring is a connection 30 to compressed air andon the other side of the knockout ring may be vacuum or air at ambienttemperature and pressure. After the surplus material has been cut fromthe can, compressed air is conducted through the conduit in the housingand into the area behind the knockout ring, thereby forcing the knockoutring forward and ejecting the scrap material from the apparatus. Thescrap material may be collected in a wastebasket or the like.

The operation of my device is as follows: the can holding means takes acan and pushes it through the guiding ring into the area inside thestationary cutting ring. At this stage, the inside cutter is locateddead center on the axis of the rotating main shaft. The shaft is rotatedby its pulley at all times. Now, the air piston shifts the bifurcatedelement forward causing the trunnions to move forward and carry with thetrunnions the ring actuator and the ring mounted on the sleeve. Thesleeve moves forward, the stationary pin of the stud rides upward on thecam in the forward end of the sleeve. This causes the stud shaft to moreaway from the centerline of the main shaft 10. The stud shaft movesprogressively away from the centerline of the pin until the cutter,which is mounted on the stud shaft, begins to cut the can. The can iscut by the inside cutter and the stationary outside cutter. After thecan has been cut, the stud shaft returns to center position. While thestud shaft is returning to its center position, the can holding meansmoves away from the cuttingapparatus or the outside cutter. Compressedair is connected to the conduit leading to the power chamber to one sideof the knockout ring apparatus. The knockout ring is moved from left toright, pushing the scrap can end before it. The scrap can end is caughtin some waste container mounted below my apparatus. Now the apparatus isready to begin a new cycle.

Shown in FIG. 2 is a cross section along the line 22 of FIG. 1, showingthe trunnion 23, trunnion ring 22, and housing apparatus 24. The sleeve20 is mounted inside the trunnion ring and moves with the trunnion ring.The shaft 10 is located centrally of the apparatus and the bifurcatedshifting elements 25 are shown in part section.

FIG. 3 shows my device taken along the line 33 of FIG. 1. The guide 4obscures the cutting edge, the stationary outside cutting ring, as itextends completely around the entrance to this area. The air cylinder isshown mounted above the apparatus and in the view of FIG. 4, shownbelow, is the stud and stud shaft 9 mounted in the rotating shaft 10.The hole 31 for the pins 15, 16 is likewise shown.

The part of the can which extends into the slot becomes scrap after thecutting operation takes place, and it is severed from the rest of thecan.

During the whole operation, the inside cutter is turning at a highspeed. The inside cutter is mounted on the stud shaft. The stud shaft ismounted on the arbor shaftn'lhe arbor shaft is turned by a pulley andthe arbor shaft and stud shaft are constantly rotating. After the canhas been moved the appropriate distance in through the outside ringcutter, the high-speed inside cutter is gradually moved offcenter bymeans of a built-in cam.

As the can moves forward, the inside cutter is moved into a more andmore eccentric position, and as it whirls around, it separates thesurplus can material from the rest of the can. The inside cutter cutsagainst the outside ring and leaves few, if any, slivers. As the scrapmaterial is sheared off the end of the can, and after this operation iscompleted, a cutter moves back into its center position along thecenterline and then, together with the trim head, and sheared off scrap,the cutter retracts.

While the trim head is retracting, air is admitted to the knockout ringthrough an opening in the housing. When air is admitted, the knockoutning moves the scrap ring forward. The scrap ring falls from the machineinto a scrap container.

Some of the advantages of this machine are: ready disposition of thescrap ring cutoff of the can, the elimination of slivers created duringtrimming, a burr, if any, only on the outside of the can, thusfacilitating cleaning, and easy elimination of the scrap ring.

The foregoing is a description of an illustrative embodiment of theinvention, and it is applicant's intention in the appended claims tocover all forms which fall within the scope of the invention.

What is claimed is:

1. In an apparatus for trimming the end of a can and having a cuttingring, a main shaft, a sleeve around the main shaft, a stud shaft havinga first end slidably attached to the main shaft, a cutter attached to asecond end of the stud shaft, the improvement comprising:

a first groove of varying depth extending along the length of the insideof said sleeve,

a T-shaped slot in the end of the main shaft,

a T-shaped fitting on the first end of said stud shaft for sliding inthe slot of said main shaft whereby said stud shaft is slidably joinedto said main shaft,

a passageway through said stud shaft in a plane perpendicular to theaxis of rotation of said main shaft,

a fixed pin mounted in said passageway and projecting from saidpassageway into said first groove,

a movable pin mounted in said passageway,

compression spring means mounted in said passageway between said movablepin and said fixed pin for urging said movable pin out of saidpassageway whereby said movable pin presses against the side of saidsleeve and urges said stud shaft and cutter toward the cutting ring toshear off the excess material from the end of the can.

2. An apparatus for cutting a tubular workpiece as set forth in claim 1further comprising:

a trunnion ring mounted about said sleeve and attached to said sleevefor moving said sleeve toward and away from said cutting ring.

3. An apparatus for cutting a tubular workpiece as set forth in claim 2in which said first groove comprises:

cam means located on the inside of said sleeve adjacent said movable pinwhereby as said sleeve is moved away from said cutting ring said fixedpin rides down the cam surface toward the outside of said sleevecarrying said stud shaft and said cutter with it toward cuttingcooperation with said cutting ring and as said sleeve is moved towardsaid ring said fixed pin rides up said cam surface toward thelongitudinal axis of said sleeve carrying said stud shaft and cutterwith it.

4. An apparatus for cutting a tubular workpiece as set forth in claim 3further comprising:

a bifurcated means for moving said trunnion ring toward and away fromsaid cutting ring,

trunnion bearing means mounted on opposing sides of said trunnion ringfor cooperation with said bifurcated means whereby motion of saidbifurcated means is imparted to said trunnion ring and thus to saidsleeve. 5. An apparatus for cutting a tubular workpiece as set forth inclaim 1 further comprising:

ejection means for ejecting the cutoff portion of a tubular workpiecefrom adjacent said cutting ring after said rotary cutter has cut thetubular workpiece and separated said cutoff portion from said tubularworkpiece and said cutter has returned from its cutting position to acentral position as said sleeve has retracted from the neighborhood ofsaid cutting ring and said fixed pin has slid down said cam surface onsaid sleeve. 6. An apparatus for cutting a tubular workpiece as setforth in claim 5 in which said ejection means comprises:

a knockout ring means for pressing the cutoff portion of said tubularworkpiece out of said apparatus. 7. An apparatus for cutting a tubularworkpiece as set forth in claim 6 comprising further:

an air chamber located behind and adjacent to said knockout ring meansfor pressing said knockout ring against said cutoff portion of saidworkpiece and expelling said cutoff portion from said apparatus.

8. A can end trimming device comprising:

an outer cutting ring forming an orifice and attached to the casing ofthe can end trimming device,

can holding means for moving an untrimmed can into the outer cuttingring and for moving the trimmed can away from the outer cutting ringafter the surplus material has been removed from said can,

a main shaft mounted for rotation about its axis and having a T-shapedslot in one end, i

a stud shaft having a first end and a second end and having a T-shapedfitting at said first end for sliding in said slot whereby said studshaft is slidably joined to said main shaft,

a rotatable cutter mounted on the second end of said stud shaft,

a passageway through said stud shaft and extending normal to the axis ofsaid main shaft,

a movable pin mounted in said passageway,

a fixed pin mounted in said passageway and extending out of said studshaft a short distance,

a compression spring mounted in said passageway between said movable pinand said fixed pin for urging said movable pin outwardly from said studshaft,

a sleeve mounted about said main shaft,

a first groove of varying depth extending longitudinally of said sleevealong the interior of said sleeve whereby said fixed pin rides in saidgroove to move said stud shaft and said rotatable cutter to and fromcutting position against the side of said can end, and

a second groove of uniform depth extends longitudinally of said sleeveon the opposite side of said sleeve from said first groove whereby saidmovable pin rides in said second groove while the main shaft and sleeveturns and when said fixed pin rides down the varying depth of said firstgroove then said compression spring urges said stud shaft outwardly tocause said cutter to engage and sever said can side against said outercutting ring.

1. In an apparatus for trimming the end of a can and having a cuttingring, a main shaft, a sleeve around the main shaft, a stud shaft havinga first end slidably attached to the main shaft, a cutter attached to asecond end of the stud shaft, the improvement comprising: a first grooveof varying depth extending along the length of the inside of saidsleeve, a T-shaped slot in the end of the main shaft, a T-shaped fittingon the first end of said stud shaft for sliding in the slot of said mainshaft whereby said stud shaft is slidably joined to said main shaft, apassageway through said stud shaft in a plane perpendicular to the axisof rotation of said main shaft, a fixed pin mounted in said passagewayand projecting from said passageway into said first groove, a movablepin mounted in said passageway, compression spring means mounted in saidpassageway between said movable pin and said fixed pin for urging saidmovable pin out of said passageway whereby said movable pin pressesagainst the side of said sleeve and urges said stud shaft and cuttertoward the cutting ring to shear off the excess material from the end ofthe can.
 2. An apparatus for cutting a tubular workpiece as set forth inclaim 1 further comprising: a trunnion ring mounted about said sleeveand attached to said sleeve for moving said sleeve toward and away fromsaid cutting ring.
 3. An apparatus for cutting a tubular workpiece asset forth in claim 2 in which said first groove comprises: cam meanslocated on the inside of said sleeve adjacent said movable pin wherebyas said sleeve is moved away from said cutting ring said fixed pin ridesdown the cam surface toward the outside of said Sleeve carrying saidstud shaft and said cutter with it toward cutting cooperation with saidcutting ring and as said sleeve is moved toward said ring said fixed pinrides up said cam surface toward the longitudinal axis of said sleevecarrying said stud shaft and cutter with it.
 4. An apparatus for cuttinga tubular workpiece as set forth in claim 3 further comprising: abifurcated means for moving said trunnion ring toward and away from saidcutting ring, trunnion bearing means mounted on opposing sides of saidtrunnion ring for cooperation with said bifurcated means whereby motionof said bifurcated means is imparted to said trunnion ring and thus tosaid sleeve.
 5. An apparatus for cutting a tubular workpiece as setforth in claim 1 further comprising: ejection means for ejecting thecutoff portion of a tubular workpiece from adjacent said cutting ringafter said rotary cutter has cut the tubular workpiece and separatedsaid cutoff portion from said tubular workpiece and said cutter hasreturned from its cutting position to a central position as said sleevehas retracted from the neighborhood of said cutting ring and said fixedpin has slid down said cam surface on said sleeve.
 6. An apparatus forcutting a tubular workpiece as set forth in claim 5 in which saidejection means comprises: a knockout ring means for pressing the cutoffportion of said tubular workpiece out of said apparatus.
 7. An apparatusfor cutting a tubular workpiece as set forth in claim 6 comprisingfurther: an air chamber located behind and adjacent to said knockoutring means for pressing said knockout ring against said cutoff portionof said workpiece and expelling said cutoff portion from said apparatus.8. A can end trimming device comprising: an outer cutting ring formingan orifice and attached to the casing of the can end trimming device,can holding means for moving an untrimmed can into the outer cuttingring and for moving the trimmed can away from the outer cutting ringafter the surplus material has been removed from said can, a main shaftmounted for rotation about its axis and having a T-shaped slot in oneend, a stud shaft having a first end and a second end and having aT-shaped fitting at said first end for sliding in said slot whereby saidstud shaft is slidably joined to said main shaft, a rotatable cuttermounted on the second end of said stud shaft, a passageway through saidstud shaft and extending normal to the axis of said main shaft, amovable pin mounted in said passageway, a fixed pin mounted in saidpassageway and extending out of said stud shaft a short distance, acompression spring mounted in said passageway between said movable pinand said fixed pin for urging said movable pin outwardly from said studshaft, a sleeve mounted about said main shaft, a first groove of varyingdepth extending longitudinally of said sleeve along the interior of saidsleeve whereby said fixed pin rides in said groove to move said studshaft and said rotatable cutter to and from cutting position against theside of said can end, and a second groove of uniform depth extendslongitudinally of said sleeve on the opposite side of said sleeve fromsaid first groove whereby said movable pin rides in said second groovewhile the main shaft and sleeve turns and when said fixed pin rides downthe varying depth of said first groove then said compression springurges said stud shaft outwardly to cause said cutter to engage and seversaid can side against said outer cutting ring.